Q.How Do I Save a Silver Maple That Has Bark Damage?
My little brother and his friend took a hammer and knocked the bark off of our silver maple. The wound is about 4 feet long and about 2 feet wide. It happened about 4 days ago and the leaves are starting to turn silver/grey and the limbs are drooping. I have heard that I should spray paint the entire wound, but I’m not sure and I don’t want to do any further damage. Help, please!!!

Here is some information, good luck!
https://www.gardeningknowhow.com/ornamental/trees/tgen/repairing-tree-bark-damage.htm